Purpose: Design of experiment (DOE) represent very powerful tool for process improvement vastly supported by six sigma methodology. This approach is mostly used by large and manufacturing orientated companies. Presented research is focused on use of DOE in truck company, which is medium size and service orientated. Such study has several purposes. Firstly, detailed description of improvement effort based on DOE can be used as a methodological framework for companies similar to researched one. Secondly, it provides example of successfully implemented low cost design of experiment practise. Moreover, performed experiment identifies key factors, which influence the lifetime of truck tyres.
Design/methodology: The research in this paper is based on experiment conducted in Slovakian Truck Company. It provides detailed case study of whole improvement effort, together with problem formulation, design creation and analysis, as well as the results interpretation. The company wants to improve lifetime of the truck tyres. Next to fuel consumption, consumption of tyres and their replacement represent according to them, one of most costly processes in company. Improvement effort was made through the use of PDCA cycle. It start with analysis of current state of tyres consumption. The variability of tyres consumption based on years and types was investigated. Then the causes of tyres replacement were identified and screening DOE was conducted. After a screening design, the full factorial design of experiment was used to identify main drivers of tyres deterioration and breakdowns. Based on result of DOE, the corrective action were propose and implement.
Findings: Based on performed experiment our research describes process of tyres use and replacement. It defines main reasons for tyre breakdown and identify main drivers which influence truck tyres lifetime. Moreover it formulates corrective action to prolong tyres lifetime.
Originality: The study represents full description of problem solving procedure- from problem definition to evaluation of corrective action. It can be also understood as methodological guidelines for similar companies. Moreover it is example of good practise. It shows how to conduct low cost DOE based improvement effort in non-manufacturing company.
Barad, M., 2014. Design of Experiments (DOE)—A Valuable Multi-Purpose Methodology. Applied Mathematics, 5 pp. 2120-2129, http://dx.doi.org/10.4236/am.2014.514206.
Chompu-inwai, R., Jaimjit, B., and Premsuriyanunt, P., 2014. A combination of Material Flow Cost Accounting and design of experiments techniques in an SME: the case of a wood products manufacturing company in northern Thailand. Journal of Cleaner Production, Available through: http://dx.doi.org/10.1016/j.jclepro.2014.08.039.
Firka, D., 2011. Statistical, technical and sociological dimensions of design of experiments. The TQM Journal, 23(4) pp. 435-445.
Ilzarbe, L., 2008. Practical applications of design of experiments in the field of engineering: a bibliographical review. Quality and Reliability Engineering International, 24(4) pp. 417-28.
Johnson, L. A., Steele, J. C., 2012. Five key steps to successful design of experiments. Global Business and Organizational Excellence, 31(4), pp. 38-47.
Kleijnen, J. P., 2005. An overview of the design and analysis of simulation experiments for sensitivity analysis. European Journal of Operational Research, 164(2), pp. 287-300
Szabo, S., Ferencz, V., and Pucihar, A., 2013. Trust, Innovation and Prosperity. Quality Innovation Prosperity. 17 (2), pp. 1-8, DOI: 10.12776/qip.v17i2.224.
Tanco, M., Viles, E., Ilzarbe, L., and Álvarez, M. J., 2008. How is experimentation carried out by companies? A survey of three European regions. Quality and Reliability Engineering International, 24(8) pp. 973-981.